BACKGROUND
[0001] Generally described, computing devices and communication networks can be utilized
to exchange information. In a common application, a computing device can request content
from another computing device via the communication network. For example, a user at
a personal computing device can utilize a software browser application to request
a Web page from a server computing device via the Internet. In such embodiments, the
user computing device can be referred to as a client computing device and the server
computing device can be referred to as a content provider.
[0002] Content providers are generally motivated to provide requested content to client
computing devices often with consideration of efficient transmission of the requested
content to the client computing device and/or consideration of a cost associated with
the transmission of the content. For larger scale implementations, a content provider
may receive content requests from a high volume of client computing devices which
can place a strain on the content provider's computing resources. Additionally, the
content requested by the client computing devices may have a number of components,
which can further place additional strain on the content provider's computing resources.
[0003] With reference to an illustrative example, a requested Web page, or original content,
may be associated with a number of additional resources, such as images or videos,
that are to be displayed with the Web page. In one specific embodiment, the additional
resources of the Web page are identified by a number of embedded resource identifiers,
such as uniform resource locators ("URLs"). In turn, software on the client computing
devices typically processes embedded resource identifiers to generate requests for
the content. Often, the resource identifiers associated with the embedded resources
reference a computing device associated with the content provider such that the client
computing device would transmit the request for the additional resources to the referenced
content provider computing device. Accordingly, in order to satisfy a content request,
the content provider would provide client computing devices data associated with the
Web page as well as the data associated with the embedded resources.
[0004] Some content providers attempt to facilitate the delivery of requested content, such
as Web pages and/or resources identified in Web pages, through the utilization of
a content delivery network ("CDN") service provider. A CDN server provider typically
maintains a number of computing devices in a communication network that can maintain
content from various content providers. In turn, content providers can instruct, or
otherwise suggest to, client computing devices to request some, or all, of the content
provider's content from the CDN service provider's computing devices.
[0005] With reference to previous illustrative example, the content provider can leverage
a CDN service provider with the modification or substitution of resource identifiers
associated with the embedded resources. Specifically, the resource identifiers can
reference a computing device associated with the CDN service provider such that the
client computing device would transmit the request for the additional resources to
the referenced CDN service provider computing device. Typically, the content provider
facilitates the utilization of a CDN provider by including CDNprovider specific resources
identifiers in requested content (e.g., Web pages). This approach generally corresponds
to an "offline" process implemented by the content provider in advance of receipt
of a request for the original content from the client computing devices. Accordingly,
modifications to resource identifiers, such as to provide alternative resources identifiers
for the same CDN service provider, to provide additional information utilized by CDN
service providers in processing the request for content and/or to identify alternative
CDN service providers, can become inefficient as they typically require implementation
of the offline process the content provider.
[0006] As with content providers, CDN providers are also generally motivated to provide
requested content to client computing devices often with consideration of efficient
transmission of the requested content to the client computing device and/or consideration
of a cost associated with the transmission of the content. Accordingly, CDN service
providers often consider factors such as latency of delivery of requested content
in order to meet service level agreements or to generally improve the quality of delivery
service.
US 2003/0149581 discloses methods and systems for providing improved acceleration of web content and/or
related services.
US 2008/0086574 discloses a content delivery network for providing content objects and domain resolution.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The foregoing aspects and many of the attendant advantages of this invention will
become more readily appreciated as the same become better understood by reference
to the following detailed description, when taken in conjunction with the accompanying
drawings, wherein:
FIGURE 1 is a block diagram illustrative of content delivery environment including
a number of client computing devices, content provider, a content delivery network
service provider, and a network computing and storage provider;
FIGURE 2 is a block diagram of the content delivery environment of FIGURE 1 illustrating
the registration of a content provider with a content delivery service provider;
FIGURE 3 is a block diagram of the content delivery environment of FIGURE 1 illustrating
the generation and processing of a content request from a client computing device
to a content provider;
FIGURE 4 is a block diagram of the content delivery environment of FIGURE 1 illustrating
one embodiment of the generation and processing of a DNS query corresponding to an
embedded resource from a client computing device to a content delivery network service
provider;
FIGURES 5A-5C are block diagrams of the content delivery environment of FIGURE 1 illustrating
another embodiment of the generation and processing of a DNS query corresponding to
an embedded resource from a client computing device to a content delivery network
service provider and the subsequent generation and processing of DNS queries corresponding
to a first and a second alternative resource identifier from a client computing device
to a content delivery network;
FIGURES 6A-6B are block diagrams of the content delivery environment of FIGURE 1 illustrating
the generation and processing of embedded resource requests from a client computing
device to a content delivery network service provider;
FIGURE 7 is a flow diagram illustrative of a request routing routine implemented by
a content delivery network service provider for selecting a cache server or network
computing component; and
FIGURE 8 is a flow diagram illustrative of another embodiment of a request routing
routine implemented by a content delivery network service provider for selecting a
cache server or network computing component.
DETAILED DESCRIPTION
[0008] The present invention provides a method for request routing according to claim 1.
[0009] Generally described, the present disclosure is directed to routing of a DNS query
from a client computing device to a network computing component via a content delivery
network ("CDN) for processing requested content associated with the DNS query. Specifically,
aspects of the disclosure will be described with regard to the routing of a client
computing device DNS query within a CDN service provider domain utilizing one or more
resource identifiers which include an application identifier in a DNS portion of the
resource identifier. Although various aspects of the disclosure will be described
with regard to illustrative examples and embodiments, one skilled in the art will
appreciate that the disclosed embodiments and examples should not be construed as
limiting.
[0010] FIGURE 1 is a block diagram illustrative of content delivery environment 100 for
the management and processing of content requests. As illustrated in FIGURE 1, the
content delivery environment 100 includes a number of client computing devices 102
(generally referred to as clients) for requesting content from a content provider
and/or a CDN service provider. In an illustrative embodiment, the client computing
devices 102 can corresponds to a wide variety of computing devices including personal
computing devices, laptop computing devices, hand-held computing devices, terminal
computing devices, mobile devices, wireless devices, various electronic devices and
appliances and the like. In an illustrative embodiment, the client computing devices
102 include necessary hardware and software components for establishing communications
over a communication network 108, such as a wide area network or local area network.
For example, the client computing devices 102 may be equipped with networking equipment
and browser software applications that facilitate communications via the Internet
or an intranet.
[0011] Although not illustrated in FIGURE 1, each client computing device 102 utilizes some
type of local DNS resolver component, such as a DNS Name server, that generates the
DNS queries attributed to the client computing device. In one embodiment, the local
DNS resolver component may be provide by an enterprise network to which the client
computing device 102 belongs. In another embodiment, the local DNS resolver component
may be provided by an Internet Service Provider (ISP) that provides the communication
network connection to the client computing device 102.
[0012] The content delivery environment 100 can also include a content provider 104 in communication
with the one or more client computing devices 102 via the communication network 108.
The content provider 104 illustrated in FIGURE 1 corresponds to a logical association
of one or more computing devices associated with a content provider. Specifically,
the content provider 104 can include a web server component 110 corresponding to one
or more server computing devices for obtaining and processing requests for content
(such as Web pages) from the client computing devices 102. The content provider 104
can further include an origin server component 112 and associated storage component
114 corresponding to one or more computing devices for obtaining and processing requests
for network resources from the CDN service provider. The content provider 104 can
still further include an application server computing device 111, such as a data streaming
server, for processing streaming content requests. One skilled in the relevant art
will appreciate that the content provider 104 can be associated with various additional
computing resources, such additional computing devices for administration of content
and resources, DNS name servers, and the like. For example, although not illustrated
in FIGURE 1, the content provider 104 can be associated with one or more DNS name
server components that would be authoritative to resolve client computing device DNS
queries corresponding to a domain of the content provider.
[0013] With continued reference to FIGURE 1, the content delivery environment 100 can further
include a CDN service provider 106 in communication with the one or more client computing
devices 102 and the content provider 104 via the communication network 108. The CDN
service provider 106 illustrated in FIGURE 1 corresponds to a logical association
of one or more computing devices associated with a CDN service provider. Specifically,
the CDN service provider 106 can include a number of Point of Presence ("POP") locations
116, 122, 128 that correspond to nodes on the communication network 108. Each CDN
POP 116, 122, 128 includes a DNS component 118, 124, 130 made up of a number of DNS
server computing devices for resolving DNS queries from the client computers 102.
Each CDN POP 116, 122, 128 also includes a resource cache component 120, 126, 132
made up of a number of cache server computing devices for storing resources from content
providers and transmitting various requested resources to various client computers.
The DNS components 118, 124 and 130 and the resource cache components 120, 126, 132
may further include additional software and/or hardware components that facilitate
communications including, but not limited to, load balancing or load sharing software/hardware
components.
[0014] In an illustrative embodiment, the DNS component 118, 124, 130 and resource cache
component 120, 126, 132 are considered to be logically grouped, regardless of whether
the components, or portions of the components, are physically separate. Additionally,
although the CDN POPs 116, 122, 128 are illustrated in FIGURE 1 as logically associated
with the CDN Provider 106, the CDN POPs will be geographically distributed throughout
the communication network 108 in a manner to best serve various demographics of client
computing devices 102. Additionally, one skilled in the relevant art will appreciate
that the CDN service provider 106 can be associated with various additional computing
resources, such additional computing devices for administration of content and resources,
and the like.
[0015] With further continued reference to FIGURE 1, the content delivery environment 100
can also include a network computing and storage provider 107 in communication with
the one or more client computing devices 102, the CDN service provider 106, and the
content provider 104 via the communication network 108. The network computing and
storage provider 107 illustrated in FIGURE 1 also corresponds to a logical association
of one or more computing devices associated with a network computing and storage provider.
Specifically, the network computing and storage provider 107 can include a number
of Point of Presence ("POP") locations 134, 142, 148 that correspond to nodes on the
communication network 108. Each POP 134, 142, 148 includes a network computing component
(NCC) 136, 144, 150 for hosting applications, such as data streaming applications,
via a number of instances of a virtual machine, generally referred to as an instance
of an NCC. One skilled in the relevant art will appreciate that NCC 136, 144, 150
would include physical computing device resources and software to provide the multiple
instances of a virtual machine or to dynamically cause the creation of instances of
a virtual machine. Such creation can be based on a specific request, such as from
a client computing device, or the NCC can initiate dynamic creation of an instance
of a virtual machine on its own. Each NCC POP 134, 142, 148 also includes a storage
component 140, 146, 152 made up of a number of storage devices for storing resources
from content providers which will be processed by an instance of an NCC 136, 144,
150 and transmitted to various client computers. The NCCs 136, 144, 150 and the storage
components 140, 146, 152 may further include additional software and/or hardware components
that facilitate communications including, but not limited to, load balancing or load
sharing software/hardware components for selecting instances of a virtual machine
supporting a requested application and/or providing information to a DNS nameserver
to facilitate request routing.
[0016] In an illustrative embodiment, NCCs 136, 144, 150 and the storage components 140,
146, 152 are considered to be logically grouped, regardless of whether the components,
or portions of the components, are physically separate. Additionally, although the
NCC POPs 134, 142, 148 are illustrated in FIGURE 1 as logically associated with the
network computing and storage provider 107, the NCC POPs will be geographically distributed
throughout the communication network 108 in a manner to best serve various demographics
of client computing devices 102. Additionally, one skilled in the relevant art will
appreciate that the network computing and storage provider 107 can be associated with
various additional computing resources, such additional computing devices for administration
of content and resources, and the like. Even further, one skilled in the relevant
art will appreciate that the components of the network computing and storage provider
107 and components of the CDN service provider 106 can be managed by the same or different
entities.
[0017] With reference now to FIGURES 2-6, the interaction between various components of
the content delivery environment 100 of FIGURE 1 will be illustrated. For purposes
of the example, however, the illustration has been simplified such that many of the
components utilized to facilitate communications are not shown. One skilled in the
relevant art will appreciate that such components can be utilized and that additional
interactions would accordingly occur without departing from the spirit and scope of
the present disclosure.
[0018] With reference to FIGURE 2, an illustrative interaction for registration of a content
provider 104 with the CDN service provider 106 will be described. As illustrated in
FIGURE 2, the CDN content registration process begins with registration of the content
provider 104 with the CDN service provider 106. In an illustrative embodiment, the
content provider 104 utilizes a registration application program interface ("API")
to register with the CDN service provider 106 such that the CDN service provider 106
can provide content on behalf of the content provider 104. The registration API includes
the identification of the origin server 112 of the content provider 104 that will
provide requested resources to the CDN service provider 106.
[0019] One skilled in the relevant art will appreciate that upon identification of appropriate
origin servers 112, the content provider 104 can begin to direct requests for content
from client computing devices 102 to the CDN service provider 106. Specifically, in
accordance with DNS routing principles, a client computing device request corresponding
to a resource identifier would eventually be directed toward a CDN POP 116, 122, 128
associated with the CDN service provider 106. In the event that the resource cache
component 120, 126, 132 of a selected CDN POP, or the storage component 140, 146,
152 of a subsequently selected instance of an NCC 136, 144, 150 as will be described
further below, does not have a copy of a resource requested by a client computing
device 102, the resource cache component 120, 126, 132, or the storage component 140,
146, 152, will request the resource from the origin server 112 previously registered
by the content provider 104.
[0020] With continued reference to FIGURE 2, upon receiving the registration API, the CDN
service provider 106 obtains and processes the registration information. In an illustrative
embodiment, the CDN service provider 106 can then generate additional information
that will be used by the client computing devices 102 as part of the content requests.
The additional information can include, without limitation, client identifiers, such
as client identification codes, content provider identifiers, such as content provider
identification codes, executable code for processing resource identifiers, such as
script-based instructions, the like. In another embodiment, in addition or alternatively,
the additional information can include file type identifiers and/or application identifiers
which can include file type information, as well as information pertaining to a type
of application for processing the requested content or a specific instance of an application
desired for processing the requested content. Application identifiers may also include
or be associated with other additional information or requirements for selecting an
instance of an application for processing the requested content, such as quality of
service criteria which can include information as to compression rates, processing
power, processing speed, and/or bandwidth of the NCC, and the like. One skilled in
the relevant art will appreciate that various types of additional information may
be generated by the CDN service provider 106 and that the additional information may
be embodied in any one of a variety of formats.
[0021] The CDN service provider 106 returns an identification of applicable domains for
the CDN service provider (unless it has been previously provided) and any additional
information to the content provider 104. In turn, the content provider 104 can then
process the stored content with content provider specific information. In one example,
as illustrated in FIGURE 2, the content provider 104 translates resource identifiers
originally directed toward a domain of the origin server 112 to a domain corresponding
to the CDN service provider. The translated URLs are embedded into requested content
in a manner such that DNS queries for the translated URLs will resolve to a DNS server
corresponding to the CDN service provider 106 and not a DNS server corresponding to
the content provider 104. Although the translation process is illustrated in FIGURE
2, in some embodiments, the translation process may be omitted in a manner described
in greater detail below.
[0022] Generally, the identification of the resources originally directed to the content
provider 104 will be in the form of a resource identifier that can be processed by
the client computing device 102, such as through a browser software application. In
an illustrative embodiment, the resource identifiers can be in the form of a uniform
resource locator ("URL"). Because the resource identifiers are included in the requested
content directed to the content provider, the resource identifiers can be referred
to generally as the "content provider URL." For purposes of an illustrative example,
the content provider URL can identify a domain of the content provider 104 (e.g.,
contentprovider.com), generally referred to as a DNS portion of the URL, a name of
the resource to be requested (e.g., "resource.jpg") and a path where the resource
will be found (e.g., "path"), the path and resource generally referred to as a path
portion of the URL. In this illustrative example, the content provider URL has the
form of:
hnp://www.contentprovider.com/path/resource.jpg
[0023] During an illustrative translation process, the content provider URL is modified
such that requests for the resources associated with the translated URLs resolve to
a CDN POP associated with the CDN service provider 106. In one embodiment, the translated
URL identifies the domain of the CDN service provider 106 (e.g., "cdnprovider.com"),
the same name of the resource to be requested (e.g., "resource.jpg") and the same
path where the resource will be found (e.g., "path"). Additionally, the translated
URL can include additional processing information (e.g., "additional information")
in the DNS portion of the URL. The translated URL would have the form of:
http://additional_information.cdnprovider.com/path/resource.jpg
[0024] In another embodiment, the information associated with the CDN service provider 106
is included in a modified URL, such as through prepending or other techniques, such
that the translated URL can maintain all of the information associated with the original
URL. In this embodiment, the translated URL would have the form of:
http://additional_information.cdnprovider.com/www.contentprovider.com/path /resource.jpg
[0025] With reference now to FIGURE 3, after completion of the registration and translation
processes illustrated in FIGURE 2, a client computing device 102 subsequently generates
a content request that is received and processed by the content provider 104, such
as through the Web server 110. In accordance with an illustrative embodiment, the
request for content can be in accordance with common network protocols, such as the
hypertext transfer protocol ("HTTP"). Upon receipt of the content request, the content
provider 104 identifies the appropriate responsive content. In an illustrative embodiment,
the requested content can correspond to a Web page that is displayed on the client
computing device 102 via the processing of information, such as hypertext markup language
("HTML"), extensible markup language ("XML"), and the like. The requested content
can also include a number of embedded resource identifiers, described above, that
corresponds to resource objects that should be obtained by the client computing device
102 as part of the processing of the requested content. The embedded resource identifiers
can be generally referred to as original resource identifiers or original URLs.
[0026] Upon receipt of the requested content, the client computing device 102, such as through
a browser software application, begins processing any of the markup code included
in the content and attempts to acquire the resources identified by the embedded resource
identifiers. Accordingly, the first step in acquiring the content corresponds to the
issuance, by the client computing device 102 (through its local DNS resolver), of
a DNS query for the original URL resource identifier that results in the identification
of a DNS server authoritative to the "." and the "com" portions of the translated
URL. After resolving the "." and "com" portions of the embedded URL, the client computing
device 102 then issues a DNS query for the resource URL that results in the identification
of a DNS server authoritative to the ".cdnprovider" portion of the embedded URL. The
issuance of DNS queries corresponding to the "." and the "com" portions of a URL are
well known and have not been illustrated.
[0027] With reference now to FIGURE 4, in an illustrative embodiment, the successful resolution
of the "cdnprovider" portion of the original URL identifies a network address, such
as an IP address, of a DNS server associated with the CDN service provider 106. In
one embodiment, the IP address can be a specific network address unique to a DNS server
component of a POP. In another embodiment, the IP address can be shared by one or
more CDN POPs. In this embodiment, a further DNS query to the shared IP address utilizes
a one-to-many network routing schema, such as anycast, such that a specific POP will
receive the request as a function of network topology. For example, in an anycast
implementation, a DNS query issued by a client computing device 102 to a shared IP
address will arrive at a DNS server component logically having the shortest network
topology distance, often referred to as network hops, from the client computing device.
The network topology distance does not necessarily correspond to geographic distance.
However, in some embodiments, the network topology distance can be inferred to be
the shortest network distance between a client computing device 102 and a POP. It
will be appreciated by one skilled in the relevant art that a number of ways exist
to determine network topology distance.
[0028] With continued reference to FIGURE 4, in either of the above identified embodiments
(or any other embodiment), a specific DNS server in the DNS component 118 of a CDN
POP 116 receives the DNS query corresponding to the original URL from the client computing
device 102. Once one of the DNS servers in the DNS component 118 receives the request,
the specific DNS server attempts to resolve the request. In one illustrative embodiment
as shown in FIGURE 4, a specific DNS server resolves the DNS query by identifying
an IP address of a cache server component or an instance of an NCC that will process
the request for the requested resource. As described above and as will be described
further below in reference to FIGURES 6A and 6B, a selected resource cache component
or a storage component associated with an instance of an NCC can process the request
by either providing the requested resource if it is available or attempting to obtain
the requested resource from another source, such as a peer cache server computing
device or the origin server 112 of the content provider 104.
[0029] In further reference to FIGURE 4, the specific DNS server can utilize a variety of
information in selecting a resource cache component or an instance of an NCC. In one
illustrative embodiment, the DNS server can use the additional information in the
DNS portion of the resource identifier (which is used to resolve the DNS query by
the DNS server) to return an IP address of a resource cache component or an instance
of an NCC. As generally described above, the additional information can include, without
limitation, client identifiers, such as client identification codes, content provider
identifiers, such as content provider identification codes, executable code for processing
resource identifiers, such as script-based instructions, and the like. In addition
or alternatively, the additional information can include file type identifiers and/or
application identifiers which can include file type information, as well as information
pertaining to a type of hosted application for processing the requested content or
a specific instance of a hosted application desired for processing the requested content.
[0030] As will be further described below in reference to FIGURE 8, where the requested
content corresponds to a streaming media file, for example, the DNS server can use
an application identifier included in a DNS portion of the first resource identifier
to select an instance of an NCC for processing the streaming media file. In one embodiment,
the application identifier can specify file type information for the content to be
processed, and the DNS server selects an instance of an NCC that has a data streaming
application capable of processing a request for the identified file type, e.g., an
MPEG or Flash media file. In another embodiment, the application identifier can specify
a type of hosted application, e.g., an Adobe Flash server streaming application or
a Real Network Helix server streaming application, to be used to process the requested
content. Based on that information, the DNS server resolves the DNS query by identifying
an instance of an NCC that corresponds to the identified type of application for processing
the requested content or that can dynamically cause creation of such an instance.
Still further, in another embodiment, the application identifier can specify a specific
instance of an application, e.g., Company's Flash server, specified by a content provider
for example. Based on that information, the DNS server then resolves the DNS query
by identifying the IP address of a specific instance of an NCC that has the application
required to process the requested content. Yet further, in another embodiment, the
DNS portion of the first resource identifier can have a separate file type identifier
which provides the file type information for use by the DNS server in selecting an
appropriate instance of an NCC device for servicing the requested content.
[0031] Even further, the DNS server can also use information obtained directly from a client
computing device (such as information provided by the client computing device or ISP)
or indirectly (such as inferred through a client computing device's IP address) to
select a resource cache component or an instance of an NCC. Such client computing
device information can, for example, be geographic information. Still further, the
DNS server components can utilize network performance metrics or measurements to assign
specific resource cache components or instances of an NCC. The IP address selected
by a DNS server component may correspond to a specific caching server in the resource
cache or a specific instance of an NCC device. Alternatively, the IP address can correspond
to a hardware/software selection component (such as a load balancer) at a specific
CDN POP or NCC POP for selecting a specific cache component or instance of an NCC.
[0032] Yet still further, for selection of an instance of an NCC, the DNS server components
can utilize additional selection information provided from network computing and storage
provider 107 to CDN service provider 106. Such selection information can include information
typically related to quality of service, such as computing capacity measurements of
NCCs, compression rates, processing power, processing speed, bandwidth, and the like,
which can be indirectly related to the cost associated with creating and/or using
a particular instance of an NCC. This additional selection information can be provided
over a communication channel between the network computing and storage provider 107
and CDN service provider 106, as generally illustrated in FIGURE 4, at a variety of
times. Moreover, as will be appreciated by one skilled in the relevant art, the additional
selection information may be transmitted in any of a number of ways, such as upon
individual requests from the CDN service provider 106, batch processing initiated
by the CDN service provider or network computing and storage provider, and the like.
[0033] In further reference to FIGURE 4, once an IP address is identified, the DNS server
118 provides the IP address of the resource cache component or the instance of an
NCC to the client computing device 102 for further processing, as will be discussed
further below in reference to FIGURES 6A and 6B.
[0034] In another illustrative embodiment, and as will be described further in reference
to FIGURES 5A-5C, the additional information included in the DNS portion of the resource
identifier can be used to identify a DNS server component which can then default to
a selection of a resource cache component of the same CDN POP or an instance of an
NCC of an associated NCC POP. The association can correspond to geographic or network
proximity.
[0035] With reference to FIGURES 5A-5C, as an alternative to selecting a resource cache
component or an instance of an NCC upon receipt of a DNS query as described in reference
to FIGURE 4, the CDN service provider 106 can maintain sets of various alternative
resource identifiers which correspond to DNS server components associated with a cache
component or an instance of an NCC that satisfy the criteria provided in the DNS portion
of the resource identifier, e.g., in an application identifier, and that will be further
selected based on additional request routing criteria. The alternative resource identifiers
can be provided by the CDN service provider 106 to the client computing device 102
such that a subsequent DNS query on the alternative resource identifier will resolve
to a different DNS server component within the CDN service provider's network. In
an illustrative embodiment, the alternative resource identifiers are in the form of
one or more canonical name ("CNAME") records. In one embodiment, each CNAME record
identifies a domain of the CDN service provider 106 (e.g., "cdnprovider.com" or "cdnprovider-1.com").
As will be explained in greater detail below, the domain in the CNAME does not need
to be the same domain found in original URL or in a previous CNAME record. Additionally,
each CNAME record includes additional information, such as request routing information,
(e.g., "request routing information"). An illustrative CNAME record can have the form
of:
request_routing_information.cdnprovider.com
[0036] In an illustrative embodiment, the CNAME records are generated and provided by the
DNS servers to identify a more appropriate DNS server of the CDN service provider
106.
[0037] In one embodiment, if the first DNS server determines that it is the appropriate
DNS server (e.g., it can resolve the DNS query by providing an IP address of a cache
component or instance of an NCC), the DNS server identifies a default, associated
cache component or instance of an NCC POP to resolve the request. Alternatively, even
though the DNS server can resolve the request, the DNS server can determine if another
DNS server can also service the request based on additional request routing criteria,
which will be described in detail below.
[0038] In one example, the CDN service provider 106 can also attempt to direct a DNS query
to DNS servers according to geographic criteria. The geographic criteria can correspond
to geographic-based regional service plans contracted between the CDN service-provider
106 and the content provider 104 in which various CDN service provider 106 POPs are
grouped into geographic regions. Accordingly, a client computing device 102 DNS query
received in a region not corresponding to the content provider's regional plan may
be better processed by a DNS server in a region corresponding to the content provider's
regional plan. In this example, the DNS server component 118 may also obtain geographic
information from the client directly (such as information provided by the client computing
device or ISP) or indirectly (such as inferred through a client computing device's
IP address).
[0039] In another example, the CDN service provider 106 can also attempt to direct a DNS
query to DNS servers according to service level criteria. The service level criteria
can correspond to service or performance metrics contracted between the CDN service
provider 106 and the content provider 104. Examples of performance metrics can include
latencies of data transmission between the CDN service provider POPs and the client
computing devices 102, total data provided on behalf of the content provider 104 by
the CDN service provider POPs, error rates for data transmissions, and the like.
[0040] In still a further example, the CDN service provider 106 can attempt to direct a
DNS query to DNS servers according to network performance criteria. The network performance
criteria can correspond to measurements of network performance for transmitting data
from the CDN service provider POPs to the client computing device 102. Examples of
network performance metrics can include network data transfer latencies (measured
by the client computing device or the CDN service provider 106, network data error
rates, and the like.
[0041] In yet a further example, the receiving DNS server can attempt to direct a DNS query
to another appropriate DNS query for load balancing or load sharing purposes. The
receiving DNS may obtain an identification of other CDN POPs that define an order
for such load balancing/load sharing. The list can be dynamic or periodically updated
based on current network conditions.
[0042] In yet another example, the CDN service provider 106 can attempt to direct a DNS
query associated with a resource request for processing by an instance of an NCC to
DNS servers according to selection information criteria provided by the network computing
and storage provider 107. As similarly set forth above, such selection information
can include information typically related to quality of service, such as computing
capacity measurements of NCCs, compression rates, processing power, processing speed,
bandwidth, and the like, which can be indirectly related to the cost associated with
creating and/or using a particular instance of an NCC. This selection information
can be provided over a communication channel between the network computing and storage
provider 107 and CDN service provider 106 at a variety of times. Moreover, as will
be appreciated by one skilled in the relevant art, the selection information may be
transmitted in any of a number of ways, such as upon individual requests from the
CDN service provider 106, batch processing initiated by the CDN service provider or
network computing and storage provider, and the like.
[0043] In accordance with an illustrative embodiment, the DNS server maintains a data store
that defines CNAME records for various incoming DNS queries. If a DNS query corresponding
to a particular DNS query matches an entry in the data store, the DNS server returns
a CNAME record as defined in the data store. In an illustrative embodiment, the data
store can include multiple CNAME records corresponding to a particular DNS query.
The multiple CNAME records would define a set of potential candidates that can be
returned to the client computing device. In such an embodiment, the DNS server, either
directly or via a network-based service, selects one of the CNAME records defined
in the data store as more appropriate routing information based on logic that factors
information contained in a DNS portion of the first resource identifier, as described
above. It will be appreciated by one skilled in the art and others that the DNS server
can implement further additional logic in selecting an appropriate CNAME from a set
of possible of CNAMEs. In an illustrative embodiment, each DNS server component 118,
124, 130 maintains the same data stores that define CNAME records, which can be managed
centrally by the CDN service provider 106. Alternatively, each DNS server component
118, 124, 130 can have POP specific data stores that define CNAME records, which can
be managed centrally by the CDN service provider 106 or locally at the POP 116, 122,
128. Still further, each DNS server computing device within the DNS server components
118, 124, 130 can utilize shared data stores managed by a respective POP or a local
data store specific to an individual DNS server computing device.
[0044] The returned CNAME can also include request routing information that is different
from or in addition to the information provided in the URL/CNAME of the current DNS
query. For example, if the CNAME selection is further based on a service level plan,
in addition to information associated with an application identifier included in the
first resource identifier, a specific further identifier can be included in the "request_routing_information"
portion of the CNAME record. An illustrative CNAME record in this specific example
can have the form of:
serviceplan.appID.cdnprovider.com
[0045] In another embodiment, request routing information can be found in the identification
of a CDN service provider 106 domain different from the domain found in the current
URL/CNAME. For example, if the CNAME is based on a regional plan, a specific regional
plan domain (e.g., "cdnprovder-regionl.com") could be used in the domain name portion
of the specific CNAME record. One skilled in the relevant art will appreciate that
additional or alternative techniques and/or combination of techniques may be used
to include the additional request routing information in the CNAME record that is
selected by the DNS server component 118.
[0046] With continued reference to FIGURE 5A, in accordance with the embodiments set forth
above, the DNS server may select (or otherwise obtain) a CNAME record that is intended
to resolve to a more appropriate DNS server of the CDN service provider 106. It may
be possible, however, that the same DNS server would also be authoritative for the
subsequent DNS query for the CNAME to be provided to the client computing device.
For example, a specific DNS server may be authoritative for both a specific regional
plan and a service level plan. Thus, returning a CNAME would still result in the DNS
query arriving at the same DNS query (which may also be due in part to the client
computing device's geography). In such an embodiment, the DNS server, such as DNS
server component 118, may choose to resolve the future DNS query in advance.
[0047] With reference now to FIGURE 5B, upon receipt of the CNAME from the DNS server component
118, the client computing device 102 generates a subsequent DNS query corresponding
to the CNAME. As previously discussed with regard to FIGURE 4, the DNS query process
could first start with DNS queries for the "." and "com" portions, followed by a query
for the "cdnprovider" portion of the CNAME. To the extent, however, that the results
of a previous DNS queries can be cached (and remain valid), the client computing device
102 can utilize the cached information and does not need to repeat the entire process.
However, at some point, depending on whether the CNAME provided by DNS server component
118 (FIGURE 5A) and the previous URL/CNAME share common CDN service provider domains,
the current CNAME DNS query resolves to a different POP provided by the CDN service
provider 106. As illustrated in FIGURE 5B, the DNS server component 124 of CDN POP
122 receives the current CNAME based on the different information in the current CNAME
previously provided by the DNS server component 118. As previously described, the
DNS server component 124 can then determine whether to resolve the DNS query on the
CNAME with an IP address of a cache component or an instance of an NCC that will process
the content request or whether to provide another alternative resource identifier
selected in the manners described above.
[0048] For purposes of illustration, assume that the DNS server component 124 determines
that the DNS query corresponding to the current CNAME (provided by DNS server component
118) also corresponds to a CNAME record in its data store. In such an example, the
DNS server component 124 would do any necessary processing to select a specific CNAME
as described above and return the CNAME to the client computing device. With reference
now to FIGURE 5C, the client computing device 102 would now transmit a second subsequent
DNS query corresponding to the CNAME provided by DNS server component 124 (FIGURE
5B). In accordance with DNS query processes already described, the DNS query would
illustratively be received by the DNS server component 130 of CDN POP 128. Again,
the DNS server component 130 can then determine whether to resolve the DNS query on
the CNAME with an IP address of a cache component or an instance of a NCC that will
process the content request or whether to provide another alternative resource identifier
selected in the manners described above. In this example, the DNS server component
130 returns an IP address.
[0049] With continued reference to FIGURE 5C, in an illustrative embodiment, the DNS server
components, such as DNS server component 130, can utilize a variety of information
in selecting a resource cache component or an instance of an NCC, as similarly set
forth above. In one example, the DNS server component can default to a selection of
a resource cache component of the same CDN POP or an instance of an NCC associated
with the same CDN POP.
[0050] With reference now to FIGURES 6A, in an illustrative example, assume that the DNS
server component 130 has selected the resource cache component 120 of POP 116. Upon
receipt of the IP address for the resource cache component 120, the client computing
device 102 transmits a request for the content to the resource cache component 120.
The resource cache component 120 processes the request in a manner described above
and the requested content is transmitted to the client computing device 102.
[0051] With reference now to FIGURES 6B, in a further illustrative example, assume that
the DNS server component 130 has selected an instance of NCC 136 of NCC POP 134. Upon
receipt of the IP address for the instance of NCC 136, the client computing device
102 transmits a request for the requested content to the instance of NCC 136. The
instance of NCC 136 processes the request and the requested content is transmitted
to the client computing device 102. For example, for streaming media, the instance
of the NCC will begin streaming the content.
[0052] With reference now to FIGURE 7, a request routine 700 implemented by the CDN provider
106 will be described. One skilled in the relevant art will appreciate that actions/steps
outlined for routine 700 may be implemented by one or many computing devices/components
that are associated with the CDN service provider 106. Accordingly, routine 700 has
been logically associated as being performed by the CDN service provider 106.
[0053] At block 702, one of the DNS server components 118, 124, 130 receives a DNS query
corresponding to a resource identifier. As previously discussed, the resource identifier
can be a URL that has been embedded in content requested by the client computing device
102 and previously provided by the content provider 104. Alternatively, the resource
identifier can also correspond to a CNAME provided by a content provider DNS server
in response to a DNS query previously received from the client computing device 102.
At decision block 704, a test is conducted to determine whether the current DNS server
is authoritative to resolve the DNS query. In an illustrative embodiment, the DNS
server can determine whether it is authoritative to resolve the DNS query if there
are no CNAME records corresponding to the received resource identifier. Additional
methodologies may also be practiced to determine whether the DNS server is authoritative.
[0054] If the current DNS server is authoritative (including a determination that the same
DNS server will be authoritative for subsequent DNS queries), the current DNS server
resolves the DNS query by returning the IP address of a default cache server component
or a default instance of an NCC. In a non-limiting manner, a number of methodologies
for selecting an appropriate resource cache component or instance of an NCC have been
previously discussed. Additionally, as described above, the IP address can correspond
to a hardware/software selection component (such as a load balancer) at a specific
CDN POP or NCC POP for selecting a specific cache component or instance of an NCC.
[0055] Alternatively, if at decision block 704 the DNS server is not authoritative, at block
808, the DNS server component selects and transmits an alternative resource identifier.
As described above, the DNS server component can utilize a data store to identify
an appropriate CNAME as a function of the current DNS query, including for example
the application identifier in the DNS portion of the URL or CNAME. Additionally, the
DNS server component can also implement additional logical processing to select from
a set of potential CNAMES. At block 710, different DNS server components 118, 124,
130 receive a DNS query corresponding to the CNAME. The routine 700 then returns to
decision block 704 and continues to repeat as appropriate.
[0056] With reference now to FIGURE 8, a request routine 800 implemented by the CDN provider
106 will be described. One skilled in the relevant art will appreciate that actions/steps
outlined for routine 800 may be implemented by one or many computing devices/components
that are associated with the CDN service provider 106. Accordingly, routine 800 has
been logically associated as being performed by the CDN service provider 106.
[0057] At block 802, one of the DNS server components 118, 124, 130 receives a DNS query
corresponding to a resource identifier. Again, as previously discussed, the resource
identifier can be a URL that has been embedded in content requested by the client
computing device 102 and previously provided by the content provider 104. Alternatively,
the resource identifier can also correspond to a CNAME provided by a content provider
DNS server in response to a DNS query previously received from the client computing
device 102. At block 804, the current DNS server selects a resource cache component
or an instance of an NCC to service the request associated with the DNS query. As
described above, the DNS server makes this selection as a function of a DNS portion
of the resource identifier associated with the DNS query. As an example, the DNS portion
of the resource identifier can specify information associated with the file type of
the requested resource or an application type or specific instance of an application
for processing the requested resource. As further set forth above, a number of other
factors may additionally be taken into consideration for selecting the appropriate
cache component or instance of an NCC for servicing the resource request.
[0058] Next, at block 806, the DNS server provides information to the client computing device
identifying the selected resource cache component or instance of an NCC. In one embodiment,
this information includes the IP address of the resource cache component or instance
of an NCC. Thereafter, the client computing device can use that information to request
and receive the requested resource. Routine 800 ends at block 806.
[0059] While illustrative embodiments have been disclosed and discussed, one skilled in
the relevant art will appreciate that additional or alternative embodiments may be
implemented within the scope of the present invention. Additionally, although many
embodiments have been indicated as illustrative, one skilled in the relevant art will
appreciate that the illustrative embodiments do not need to be combined or implemented
together. As such, some illustrative embodiments do not need to be utilized or implemented
in accordance with scope of variations to the present disclosure.
[0060] Conditional language, such as, among others, "can," "could," "might," or "may," unless
specifically stated otherwise, or otherwise understood within the context as used,
is generally intended to convey that certain embodiments include, while other embodiments
do not include, certain features, elements and/or steps. Thus, such conditional language
is not generally intended to imply that features, elements and/or steps are in any
way required for one or more embodiments or that one or more embodiments necessarily
include logic for deciding, with or without user input or prompting, whether these
features, elements and/or steps are included or are to be performed in any particular
embodiment.
[0061] Any process descriptions, elements, or blocks in the flow diagrams described herein
and/or depicted in the attached FIGURES should be understood as potentially representing
modules, segments, or portions of code which include one or more executable instructions
for implementing specific logical functions or steps in the process. Alternate implementations
are included within the scope of the embodiments described herein in which elements
or functions may be deleted, executed out of order from that shown or discussed, including
substantially concurrently or in reverse order, depending on the functionality involved,
as would be understood by those skilled in the art. It will further be appreciated
that the data and/or components described above may be stored on a computer-readable
medium and loaded into memory of the computing device using a drive mechanism associated
with a computer readable storing the computer executable components such as a CD-ROM,
DVD-ROM, or network interface further, the component and/or data can be included in
a single device or distributed in any manner. Accordingly, general purpose computing
devices may be configured to implement the processes, algorithms and methodology of
the present disclosure with the processing and/or execution of the various data and/or
components described above.
1. Verfahren zum Anfordern von Routing, das Folgendes umfasst:
Erhalten einer DNS-Anfrage von einer Client-Rechenvorrichtung (102) bei einem ersten
DNS-Server (118), wobei die DNS-Anfrage einem angeforderten Betriebsmittel mit einer
ersten Betriebsmittelkennung entspricht und wobei der erste DNS-Server in einem Netzdienstanbieter
(106) zur Bereitstellung von Inhalten enthalten ist;
Bestimmen, dass die erste Betriebsmittelkennung einer alternativen Betriebsmittelkennung
zugeordnet ist, durch
Erhalten von Betriebsmittel-Routing-Informationen, die einer Anwendungskennung entsprechen,
die in der ersten Betriebsmittelkennung enthalten ist; und
Auswählen einer alternativen Betriebsmittelkennung als eine Funktion der Betriebsmittel-Routing-Informationen,
die der Anwendungskennung entsprechen;
Senden der alternativen Betriebsmittelkennung zu der Client-Berechnungseinrichtung,
wobei die alternative Betriebsmittelkennung Informationen für das Bewirken, dass eine
DNS-Anfrage zu einer Domäne aufgelöst wird, die dem Netzdienstanbieter zur Bereitstellung
von Inhalten entspricht, und ergänzende Anforderungs-Routing-Informationen, die nicht
in der ersten Betriebsmittelkennung enthalten sind, enthält;
Erhalten einer nachfolgenden DNS-Anfrage von der Klient-Berechnungseinrichtung bei
einem zweiten DNS-Server (124), wobei die nachfolgende DNS-Anfrage der alternativen
Betriebsmittelkennung, die durch den Netzdienstanbieter zur Bereitstellung von Inhalten
bereitgestellt wird, entspricht und der zweite DNS-Server in dem Netzdienstanbieter
zur Bereitstellung von Inhalten enthalten ist;
Auflösen der nachfolgenden DNS-Anfrage bei dem zweiten DNS-Server, um eine Netzberechnungskomponente
(136, 144, 150) für das Verarbeiten und Bereitstellen von Inhalt, der der ursprünglichen
Betriebsmittelanforderung zugeordnet ist, zu identifizieren; und
Senden von Informationen, die die identifizierte Netzberechnungskomponente identifizieren,
zu der Client-Berechnungseinrichtung.
2. Verfahren nach Anspruch 1, wobei die erste Betriebsmittelkennung einem Uniform-Resource-Locator
derart entspricht, dass die DNS-Anfrage zu einer Domäne aufgelöst wird, die dem Netzdienstanbieter
zur Bereitstellung von Inhalten entspricht.
3. Verfahren nach Anspruch 1, wobei die alternative Betriebsmittelkennung einer kanonischen
Namenseintragskennung entspricht.
4. Verfahren nach Anspruch 1, wobei die Netzberechnungskomponente eine Anwendung zum
Verarbeiten des angeforderten Betriebsmittels umfasst.
5. Verfahren nach Anspruch 4, wobei die Anwendung eine Anwendung zum Streamen von Daten
ist.
6. Verfahren nach Anspruch 1, wobei die Netzberechnungskomponente betreibbar ist, das
Erstellen einer Instanz einer virtuellen Maschine zum Verarbeiten des angeforderten
Betriebsmittels dynamisch zu bewirken.
7. Verfahren nach Anspruch 1, wobei die Anwendungskennung Informationen enthält, die
dem Dateityp des angeforderten Betriebsmittels zugeordnet sind, und die alternative
Betriebsmittelkennung als eine Funktion des Dateityps des angeforderten Betriebsmittels
ausgewählt wird.
8. Verfahren nach Anspruch 1, wobei die Anwendungskennung Informationen enthält, die
einem Anwendungstyp für das Verarbeiten des angeforderten Betriebsmittels zugeordnet
sind, und die alternative Betriebsmittelkennung als eine Funktion des Anwendungstyps
ausgewählt wird.
9. Verfahren nach Anspruch 1, wobei die Anwendungskennung Informationen enthält, die
eine Instanz einer Anwendung für das Verarbeiten des angeforderten Betriebsmittels
identifizieren, und die alternative Betriebsmittelkennung als eine Funktion der Anwendungsinstanz
ausgewählt wird.
10. Verfahren nach Anspruch 1, wobei die Anwendungskennung Netzberechnungskomponenten-Auswahlinformationen
enthält, die einem Typ einer Anwendung oder einer Instanz einer Anwendung zum Verarbeiten
des angeforderten Betriebsmittels zugeordnet sind.
11. Verfahren nach Anspruch 10, wobei die Auswahlinformationen Dienstqualitätsinformationen
enthalten.
12. Verfahren nach Anspruch 1, das ferner das Erhalten von Betriebsmittel-Routing-Informationen,
die der Client-Berechnungseinrichtung, die der DNS-Anfrage zugeordnet ist, entsprechen,
umfasst, wobei die Informationen, die der Client-Berechnungseinrichtung entsprechen,
einem geographischen Ort der Client-Berechnungseinrichtung zugeordnet sind und das
Auswählen einer alternativen Betriebsmittelkennung ferner auf der Grundlage von Informationen,
die dem geographischen Ort der Client-Berechnungseinrichtung zugeordnet sind, erfolgt.